1. Field of the Invention
The present invention relates to an engine service tool kit. More specifically to a unique service tool kit to perform synchronizing, fuel setting and fuel timing adjustments on a 3116 diesel truck engine.
2. Background of the Invention
A tune-up of the 3116 diesel truck engine includes three measurements that must be made with a dial indicator on the injectors. These measurements are synchronization, fuel timing, and fuel setting.
Injector synchronization is the setting of each injector rack to a reference position so each injector delivers the same amount of fuel to the respective cylinder. Synchronization is accomplished by setting each injector rack to a predetermined position while the control linkage connecting all of the injectors is in a reference fixed position. This reference position is called the synchronizing or fuel shutoff position.
The control linkage is in the synchronizing position when the injector of the No. 1 injector is at fuel shut,off with a rack stop bar in contact with an injector base for the No. 1 injector. The rack stop bar projects from a rack head which is coupled to an injector rack control linkage. The injector rack control linkage for each cylinder is mounted on a common spring biased injector rack shaft. Since the No. 1 injector is the reference point for the other injectors, no synchronizing adjustment is made on the No. 1 injector.
However, to maintain the No. 1 injector in the fuel shutoff synchronizing position, the spring bias of the, injector rack shaft and the rack stop bar must be overcome. Previously, the technician or mechanic physically overcame the spring bias by manually holding the rack stop bar against the injector base. The technician had to keep constant contact of the rack head to keep the rack stop bar in contact with the injector base of the No. 1 injector with one of his hands while the delicate adjustments of synchronizing the remaining injectors are made with the other hand.
Furthermore, an injector must be synchronized each time it has been removed and reinstalled or replaced. If the No. 1 injector is removed or replaced, all the injectors must be synchronized. The synchronizing procedure required the removal of the rocker arm assemblies for the No. 1 injector and for each of the injectors to be synchronized. Removal of the rocker arm assemblies provides greater access for the technician to the control linkage and injector rack head, but is a very time consuming procedure. Furthermore, checking the valve clearance and fuel timing is recommended after each removal and reinstallation of the rocker arm assemblies, which further burdens the technician.
When the rocker arm assemblies are removed, the rack bar cannot be moved for adjustment until bolts from the top of the cylinder head are removed and an injector spring compressor is installed using these bolt holes. Once the rocker arm assemblies are removed, these spring compressors need to be installed on the No. 1 injector and any or all of the other injectors that are to be synchronized.
Fuel setting on the 3116 diesel truck engine is accomplished by the adjustment of a fuel setting screw to provide a specified injector rack position for the No. 1 injector rack bar. The fuel setting adjustment limits the power output of the engine by setting the maximum travel of all the injector racks. Before the fuel setting is checked, the injectors must all be correctly synchronized. The fuel setting adjustment requires that a dial indicator be mounted horizontally in an indicator group fixture which includes a pivot bar. An upper end of the pivot bar contacts a terminal end of a shaft on the dial indicator while a lower end of the pivot bar contacts an end of a rack bar which projects from the rack head and through the injector base. The dial indicator measures the rack bar position through the angular position of the pivot bar. The synchronizing and fuel setting adjustments each establish a specified measured distance between the rack bar and the injector base. Fuel setting also requires removal of the No. 1 injector rocker arm assembly to establish a reference or zero reading on the dial indicator.
Fuel timing contemplates an adjustment on each injector to measure the height of the injector spring. The measurement is the distance between the top of a spring retainer or tappet to the top of a shoulder on the injector base at a specified time. In the past, the dial indicator (used for synchronizing and fuel setting) was required to be removed from the indicator group fixture and also used for the fuel timing measurement. An "off engine", i.e., separate from the engine, timing fixture is used to set the dial indicator to a pre-determined reference measurement which is later compared to the height of each injector spring to measure the fuel timing. A bracket housing the dial indicator is mounted onto the timing fixture with the length of the indicator shaft being calibrated on a standard height timing block. The dial indicator is then adjusted to zero. The bracket housing the indicator is then transferred to each injector for a timing measurement on the height of that particular injector spring. A fuel timing adjustment screw at the opposite end of the rocker arm adjusts the height of the spring as required.